A digital broadcast receiver, such as a digital TV and a set top box (STB), has been widely used recently. As illustrated in FIG. 1, this typical digital broadcast receiver functions as the set top box that performs personal video recoding (PVR), which writes and stores a digital broadcast program in large capacity writing means such as a hard disk drive (HDD). Also, the digital broadcast receiver is connected to a satellite broadcast antenna 20 and a television 40.
The satellite broadcast antenna 20, for receiving a digital satellite broadcast re-broadcasted through a plurality of satellites, receives and outputs to a digital broadcast receiver 30 a digital satellite broadcast re-broadcasted by a transponder. The transponder receives an electric wave transmitted from a broadcast station on the ground and amplifies and re-transmits to the ground the received electric wave.
Provided in the center of the satellite broadcast antenna 20 is a low noise block down converter (LNB), which converts a frequency of 4 to 12 GHz to frequency of 1 GHz.
The digital broadcast receiver 30 restores and processes the original video and audio signals of a digital broadcast program of MPEG2 transport stream, received through the satellite broadcast antenna 20. Then, the digital broadcast receiver 30 outputs and displays the video and audio signals through a television 40 such that a user can watch a desired digital broadcast program.
The digital broadcast receiver 30 can employ two tuners to allow the user to record a channel while watching another channel. The tuner tunes satellite signals inputted through the LNB to a signal of a particular preset frequency.
However, a conventional digital broadcast receiver 30 is restricted to use the two tuners in accordance with the number of LNBs that receive satellite signals.
For example, when polarization, high band and low band are selected in one LNB, if a particular frequency (e.g. horizontal polarization and high band) is received only, all tuners tune to a specific frequency within one satellite signal.
Owing to this restriction, the digital broadcast receiver 30 requires a user to set a loop-through mode or a separate mode through a user menu. In the loop-through mode, two tuners share an LNB signal provided through one signal line. In the separate mode, each tuner independently tunes a different LNB signal provided through two signal lines.
In case that LNB signals received through the two signal lines are the same, the digital broadcast receiver 30, which has set the connection mode of the satellite signal for two tuners, makes the two tuners search for a channel or copy a channel, searched from one tuner, to the other tuner.
However, it is not easy for a general user who uses the digital broadcast receiver employing two tuners to understand the restriction. If the user wrongly sets the two tuners as the loop-through mode or separate mode, the two tuners can not function properly.